The present invention relates to reference voltage generating circuits.
In order to achieve highly accurate semiconductor circuits, especially in order to achieve highly accurate semiconductor analog circuits, reference voltage generating circuits that have extremely small variations in reference voltages to temperature change are needed.
In order to meet the above needs, a reference voltage generating circuit that has the following function is disclosed in U.S. Pat. No. 7,420,359.
A voltage that is proportional to the absolute temperature obtained from a resistor coupled to a BGR (bandgap reference) circuit, and voltages obtained by dividing the output voltage of the BGR circuit are input into a correcting circuit including a differential pair. The differential pair of the correcting circuit generates a correcting current in accordance with the difference between the input voltages that varies in accordance with temperature. By making the generated correcting current flow through a resistor coupled to the BGR circuit, the reference voltages, which are output from the BGR circuit and vary depending on temperature change, are corrected.